Short range missiles presently utilize a fuel tank and pump for storing and pumping fuel to an engine which drives a missile to its destination. Controlling the weight of these missiles is critical. It is desirable for the missile not to carry excess fuel. Further, it is desirable for the fuel tank to be able to contain and store the fuel for extended periods of time.
Flexible fluid storage tanks have been used for storing fluids in various environments. Examples of flexible fuel storage tanks are disclosed in U.S. Pat. No. 2,724,418 to Krupp, issued Nov. 22, 1955; U.S. Pat. No. 2,736,356 to Bender et al., issued Feb. 28, 1956; U.S. Pat. No. 2,851,075 to Palfey, issued Sep. 9, 1958; U.S. Pat. No. 2,884,978 to Grimm, issued May 5, 1959; U.S. Pat. No.2,915,097 to Lewis, issued Dec. 1, 1959; U.S. Pat. No. 3,978,901 to Jones, issued Sep. 7, 1976; U.S. Pat. No. 3,982,573 to Jones, issued Sep. 28, 1976; and U.S. Pat. No. 4,026,503 to Rhodes, issued May 31, 1977.
In particular, the U.S. Pat. No. 4,573,508 to Knaus, issued Mar. 4, 1986, discloses a collapsible storage tank for holding large volumes of material. The tank is fabricated in a rectangular shape from long lengths of rubberized square woven fabric. The lengths of fabric are oriented with overlapping adjacent edges to form inner and outer envelope structures which are integrally vulcanized to a homogeneous tank body.
The aforementioned prior art Patents provide no means for insuring that air will not be trapped within the bladder upon emptying. This is a critical concept for the use of such bladders as a fuel tank in short range missiles because it is desirable for the tank to carry only enough fuel as needed to send the missile to its desired destination. It is therefore critical that all of the fuel be exhausted from the bladder when required. Air pockets can displace the fuel thereby not allowing the bladder to carry the complete desired amount of fuel. Additionally, the bladder must be capable of emptying the entire contained quantity of fuel. Pockets of fuel as opposed to pockets of air, cannot be trapped within the bladder as it exhausts when it is critical that all the fuel contained within the bladder be used to insure the missile reaches its desired destination.
The present invention solves the aforementioned problems by providing a fuel storage bladder which obviates the need for a fuel pump by a rigid fuel tank, thereby requiring less weight, and further carrying the minimum amount of fuel necessary to reach a destination. The inventive bladder further provides means for decreasing stresses placed on the bladder per se during filling and exhaust of the fuel, thereby providing a flexible fuel container which can store fuel over an extended period of time.